Obviously common sense indicates that you should no more judge a car by its paint job than you should judge a book by its cover. But even so, I can't pretend that my relationship with the new Peugeot 307 Coupe Cabriolet was not affected, at least in its early stages, by the fact that the car was, overtly and undeniably, orange. "Salamanca orange," to be precise. Metallic Salamanca orange.

It could be argued that the only thing in nature that ought to be allowed to get away with being orange is an orange. And, OK, one or two flowers, And maybe the occasional parrot-part, if we must. But no cars, surely. Unless you want to appear to be driving around in a huge metal fruit. It's not like the 307 CC doesn't already draw attention to itself. Indeed, giving it further assistance in this area, in the form of a look-at-me paint job, is a bit like slapping a coat of Day-Glo on Paris Hilton: it's not strictly necessary. The car is already jumping up and down and waving, fit to burst.

Bulky at the back and snub-nosed at the front, the 307 CC must have one of the least predictable body shapes on the road. It looks like a training shoe. Less charitably, one could assert that it appeared to have left the drawing board a little prematurely. At any rate, there could, I think, under certain lighting conditions, be some room for doubt about which end was the bonnet and which end was the boot.

That is, of course, until you take off the roof - or rather, until you sink the button located behind the handbrake and watch as, to the low and unstressful whirring of an electric motor, the entire top of the car slides away and folds itself cleanly into the boot. (The entire process takes just 20 seconds, and a highly diverting 20 seconds it is too.) With the roof and all those pesky windows out of the way, the lines of the car suddenly cohere and come alive. Hey presto, your cumbersome old trainer has become a cute ballet pump. Better than that: a ballet pump with the aerodynamic properties of a toboggan.

It's at this point that one may come to have a few passing regrets about the engine - in the case of our test car, a 2.0 litre diesel. This may be a smart and enormously commendable piece of engineering in its frugality with fuel and in its stout and principled refusal to choke the leaves off trees as it passes. But it's not really built to supply the creamy smoothness of coupe-driving legend. The idea of a coupe, surely (as distinct from the harder-edged pleasures of a convertible sports car), is to generate a soft sigh, both from the engine and from wistful spectators on the pavement. It should be able, in other words, to turn itself to the role of airborne chariot at the dropping of its roof. When you've got one of Peugeot's diesel engines on board, clanking like a milkfloat crossing a cattle grid, the illusion is, at the very least, suspended.

It may well be, of course, that the sigh you require is available using some of the lardier petrol engines. (Peugeot can do you a 1.6 litre and a 2.0 litre manual version, and a 2.0 litre automatic.) But not even opting for one of those will get you round the 307's not insignificant door problem - another small detail gently sapping the car's aspirations to splendour. (And let's face it, £21,000 should buy a little splendour.)

Because the 307 CC is a coupe, the windows in the doors lack frames to keep them rigid. And because, as a result, those windows are free to twang about a bit, this has considerable acoustic implications for the closing of those doors. Bear in mind, also, that these are generously broad doors in any case, to allow for the admission of passengers to the rear seats. What the combination of these factors means is that, should you find yourself still within the car when an alighting passenger slams their door, you are likely to suffer what can only be described as major sonic trauma. It's as if someone has smacked a mallet against a corrugated pig shed - a corrugated pig shed to the wall of which, for some reason, you happened to have your ear pressed at the time. The last time I heard doors sound so horrible, I was in a hired Ford Transit with a rust problem.

Still, once your ears stop ringing, there is no escaping the fact that the 307 CC is a sweet and simple pleasure to drive - underwhelming in the acceleration department, but stable and stately, even. With the roof down and the windows up, the wind can't touch you. In this weather, I could have done without the steel gear knob, which at sub-zero temperatures long after the rest of the car had warmed up threatened to deliver a brutal attack of frost-bite to the palm. And I was, at all times, happier to be in the front rather than in the back where, Peugeot claims, there is room for two adults. Room for adult buttocks, yes; for adult shoulders, too. But it still seemed to me that the problem of what to do with adult legs remained largely unresolved. Hang them over the sides, perhaps. True, it will attract looks. But you're going to get those anyway.